Dusk closed in around me as I plugged home on my bike, aimlessly looking at the ground as I often do when lost in a daydream about fishing or some other outdoor pursuit, when I noticed a small bird pass under my pedal. It was dead, of course, and when I circled back, I discovered it was a screech owl, still as a glacier with no sign as to how it met its fate.

As I stood staring at its oval face, brilliant red-brown coloring and tell-tale ear tufts, I returned to a still spring night last year when the curtain ushering in the day's end fell and the depth of nightfall's silence was revealed. The optimum hearing level of my ears had been beaten down by the artificial sounds of sirens and traffic, but now I quickly tuned in to the natural static that is only found in wild areas. Across the thick blackness wafted the unmistakably eerie call "hoohoo-hoohoo, hoohoo-hoohoo." This continued for some time, though the cadence and frequency of the hoots varied slightly.

That quick flash of remembrance underscored how I, like many people, can be mesmerized by owls, those nocturnal animals that hold a special place among so many cultures. To Apaches, an owl dream signified approaching death. The Dakota Hidatsas saw the burrowing owl as a protective spirit for brave warriors. In English literature, the barn owl carried a sinister reputation, probably because it was a night bird and darkness was always associated with death.

Owls are members of an order of nocturnal birds of prey found throughout the world except in Antarctica. Common barn owls have one of the largest ranges among any living birds. All owls share some similarities, but they're classified in two families: the typical owls, with about 167 species; and the barn owls, with about 14 species.

For owls, eyes and ears are everything. Their large eyes are encapsulated in a circle of bone called the "sclerotic ring," which allows little eye movement. In fact, owls' eyes are so big relative to their body size that if the same proportions were found in humans, our eyes would be nearly as big as grapefruits. Because owls must turn their entire heads to look sideways, they have long and flexible necks that permit the head to rotate through 270 degrees.

Most owls hunt their prey under the cover of darkness, which makes their hearing particularly important. Many owls have asymmetrical skulls, with the ear openings at different levels. The adaptation works like sophisticated sonar, enabling the bird to get a fix on its prey. The ear openings are covered by short, densely webbed feathers that frame the face, turning it into a dish-like reflector for sound, which gives the bird sensitive, directional hearing that enables it to locate prey in total darkness.

Barn owls, which target small ground mammals and must rely on their silent flight and acute hearing to locate prey, have a velvety pile on the feather surface to muffle the sound of their wings. Also, the leading edges of the wing feathers have a fringe or fine comb that deadens the sound of the wing beats. Once barn owls find their quarry, they make short work of it, often swallowing bones and skull whole. The indigestible parts are formed into pellets that are disgorged about the nest.

Overall, owls suffer from habitat loss due to logging and development, but other threats include toxic pollutants, which weaken eggshells. I'm not sure what caused this owl to die, but as the hurried band of cars sped past, I longed for the soulful respite of the deep woods.